Answer
(a) $0.104Kg$
(b) $0.156Kg$
Work Step by Step
(a) We can find the required mass as follows:
$m=\frac{S}{g(1+\frac{r_{cm}}{r_{pc}})}$
We plug in the known values to obtain:
$m=\frac{2.54N}{(9.81)(1+\frac{30.0cm}{20.0cm})}$
$m=0.104Kg$
(b) We can find the mass of the paint can as
$M=(\frac{r_{cm}}{r_{pc}})m$
We plug in the known values to obtain:
$M=\frac{30.0cm}{20.0cm}(0.104Kg)$
$M=0.156Kg$
